tube help on a Peavey Delta Blues 2x10

[Christopher30]

Howdy
Recently I have tried replacing the tubes on my Delta Blues amp. The new pre amp tubes are doing weird things. Any two of the three new 12AX7's work under the pre and post volume channel with a certain old tube under the normal volume plug, but the amp has no sound at all with any of the new tubes under the normal volume channel. I don't think any of the new tubes are bad since the pre and post work fine in the 1st configuration with any of the new tubes in those slots. Any help anyone could give would be much appreciated.

Christopher

[Enzo]

The LEAD channel is simply the NORMAL channel with an extra tube switched in. Very odd that NORMAL doesn't work but LEAD do. ANything that would kill the normal ought to kill the lead as well. Only things coming to mind are the volume control itself or maybe a relay. None of which should have been affected by just changing tubes. BUT... coincidences happen.

Does the amp work with all the tubes being the old ones? If so, substitute each of the new ones - one at a time - into the first socket. The socket farthest from the power tubes. Now if each tube works there, then we can assume the tubes are indeed OK.

[Christopher30]

Of the three pre amp slots, the one farthest from the power tubes is the only one none of the new tubes refuse to work in. The two slots next to the power tubes work with any two of the new 12AX7's in conjunction with an old tube in the first slot. And the amp functions with all the old pre amp tubes, aside from making an annoying hum(what prompted me to change the tubes for the first time since I bought it). A friend suggested the other day that maybe taking some sandpaper and lightly brushing out the sockets might help, maybe the new tube simply was not connecting properly because of buildup in the first socket and the reason the old tube works there is because it has molded to the buildup over time? any more suggestions? The amp sounds fine now, I would like to be able to replace that tube, though.

[Amp Kat]

You can take a pick and close the contacts a hair on the sockets if they have become seperated to much of course letting it sit about 10 minutes after powering down. Some pins on tubes are different thickness and they do bend quite easily so it is possible they have been shaped to the socket. In that case your going to have to break down and eventually change them out which is quite easy once you get the board pulled out.

[Christopher30]

Thanks, I'll give it a shot and let you guys know what happens here.

Christopher

[Christopher30]

I've gotten it working by bending the plugs on the tube a bit. That particular socket still feels too loose. Any advice on how I could tighten it without taking the whole thing apart?
Thanks